The Lingtai is part of the current Leo and is made up of three stars. The word Lingtai means "observatory" in Chinese, used to observe astronomy and meteorology.

Since ancient times, the Reidai has been a place where astronomical and meteorological observations were made in order to know good or bad news in advance, and it is said to have been both an astronomical and meteorological observatory. The word "rei" also refers to the mysterious spiritual energy that lurks within astronomical and meteorological phenomena.

There is the following legend about the spirit world:

"The Son of Heaven uses the Spiritual Platform to study the mysteries of astronomy and to investigate the movements of the human world." (Wen Xuan)

It is said that this helped to eliminate those who had lost their abilities, to distinguish wise people, to reveal their virtues, and to select talents. The spirit platform was a building where fortune tellers could pray for good fortune and to ward off disasters by observing the positions of the sun, moon, and stars.

During the Han dynasty, important political buildings were historically revered and called the Three Palaces. The remains of the Lingdai in Luoyang during the Later Han dynasty were unearthed during excavations in 1974-75.